References for 1 Kings 12:25

26
Jeroboam thought to himself, "The kingdom will now likely revert to the house of David.

27
If these people go up to offer sacrifices at the temple of the LORD in Jerusalem,3 they will again give their allegiance to their lord, Rehoboam king of Judah. They will kill me and return to King Rehoboam."

References for 1 Kings 12:31

32
He instituted a festival on the fifteenth day of the eighth11 month, like the festival held in Judah, and offered sacrifices on the altar. This he did in Bethel,12 sacrificing to the calves he had made. And at Bethel he also installed priests at the high places he had made.

References for 1 Kings 12:32

33
On the fifteenth day of the eighth month, a month of his own choosing, he offered sacrifices on the altar he had built at Bethel.13 So he instituted the festival for the Israelites and went up to the altar to make offerings.